max10 on chip flash read/write in nios

hi everone, for two weeks i stuck in the max10 on chip flash read/write in nios.

in my project, it has a nios system and the clk frequency is 100mHz.

i want to use the internal configuration mode of max10(single compressed image with memory initialization), as well as read/write the chip flash UFM in nios.

i can read the UFM, but i can not write to it.

the following is my code, i run it in debug mode

flash_status_reg1=IORD_32DIRECT(ONCHIP_FLASH_0_CSR_BASE,0x0); // read the flash_status_reg, the result is 0xfffffc04,

flash_control_reg1=IORD_32DIRECT(ONCHIP_FLASH_0_CSR_BASE,0x4); // read the flash_control_reg, the result is 0x3fffffff,

flash_data_reg1=IORD_32DIRECT(ONCHIP_FLASH_0_DATA_BASE,0x0); // read the first 32 bit of UFM1,the result is 0x0,

while(1)

{

flash_status_reg1=IORD_32DIRECT(ONCHIP_FLASH_0_CSR_BASE,0x0);//read the flash_status_reg, the result is 0xfffffc04, it means read success

flash_status_reg1=flash_status_reg1&0x4;

if (flash_status_reg1== 0x4) break; // write success

}

// write to UFM1

IOWR_32DIRECT(ONCHIP_FLASH_0_CSR_BASE,0x4,0xff7fffff);// disable the write protection of UFM1

flash_control_reg1=IORD_32DIRECT(ONCHIP_FLASH_0_CSR_BASE,0x4);// read the flash_control_reg, the result is 0x3f7fffff,

IOWR_32DIRECT(ONCHIP_FLASH_0_DATA_BASE,0x0,0x12345678);// write to the first 32 bit of UFM1, then the debug stuck in here

can someone gives me some help?

i have found the reference desin for how to use the UFM　in quartus without nios;

i also have found the reference desin for how to use the onchip internal configuration mode of max10 in nios system;

but i have not found a reference desin use nios, and the UFM

thanks!